Allow system_server binder_call into hal_graphics_allocator

Test: no log spam for graphics allocator
Test: dmesg | audit2allow does not show denial for
hal_graphics_allocator_default
Test: system is responsive after boot (because
      android.hardware.graphics.allocator@2.0::IAllocator getService()
      will not be blocked)

Bug: 36220026
Change-Id: I3e103f88988fe4a94888e92ee8c5b1f27845ad9e

private/system_server.te

@@ -177,7 +177,8 @@ hwallocator_use(system_server)
 binder_call(system_server, hal_boot)
 binder_call(system_server, hal_contexthub)
 hal_client_domain(system_server, hal_fingerprint)
-binder_call(system_server, hal_gnss);
+binder_call(system_server, hal_gnss)
+binder_call(system_server, hal_graphics_allocator)
 binder_call(system_server, hal_ir)
 binder_call(system_server, hal_light)
 binder_call(system_server, hal_memtrack)